unfabled976

I am a PAYE employee but also a sole trader for a small side business. I completed my self-assessment for 2023-2024 in May 2024. My tax calculation said I owed a balancing payment of approx £12k for 2023-24, and that I will owe a payment on account in Jan 2025 of approx £6k and another payment of approx £6k in July 2025. So I owe HMRC about £18k to be paid by Jan 31st 2025. I made about £7k in payments on account in 2023-24 so subtracting those should mean I owe roughly £11k by Jan. I want to pay this now, but HMRC's self-assessment portal says that I have nothing to pay. How can this be? I want to avoid a situation in January where I get fined but it makes no sense to me. How can I make a balancing payment for last year when the SA portal says I owe nothing? I must do, surely? Is the balancing payment being taken off my PAYE earnings?